Sectional doors are well known in the art, and consist of several hinge-connected panels which slide from a closed vertical position to an open horizontal overhead position. Each panel has rollers on its side edges which move in door tracks mounted to a structure. Sectional doors are typically used in fixed structures such as home garages and commercial buildings, and also in mobile structures such as trucks and delivery vans. A motorized opening and closing mechanism can be connected near the top of the door to effect the opening and closing action. A problem however exists with sectional doors. When the door is in the open horizontal overhead position, the door blocks light from light fixtures which are mounted on the ceiling of the structure. U.S. Pat. No. 9,976,738 (which is hereby included by reference) discloses a lighting system which attaches to a sectional door and solves the aforementioned problem.
Some sectional doors do not have power openers, but rather are manually opened and held open with a large spring. Such manual sectional doors are frequently found in delivery trucks, but can also be used in other structures. A problem exists when these doors are opened; the doors can overshoot before settling back into the open position. The overshoot would cause the movable electric contactor to forcefully collide with the fixed electric contactor and result in mechanical damage to the contactors and associated components.